That would be a mistake. The Level 3 class does not cover much in the way of logic instructions. It is assumed you already know the logic used in a PLC-5/SLC 500 or Logix5000. Not having any experience with A-B and jumping into the Level 3 class would probably be a mistake.
The class he is referring to would indeed be a good starting point. It may be a little basic but gives a good start on tags, configuring modules, and editing logic.
The "kit" includes the RSTrainer software which I think provides very good refresher training. So as an occasional refresh it is a great tool. I wouldn't want to learn exlusively from RSTrainer but as another tool it fits in pretty well.
OG